I have a device called SDrive 1564 (a variant of popular SD2IEC, a SD card reader that mimics Commodore disk drive) and recently it's gotten a tad cranky, It mostly works but the LCD display is coming up garbage and sometimes I have to power cycle a few times before my C64 can find the drive. I took it apart, it is a fairly simply design with 1284P, 5v regulator (from external power rather than leeching off C64's power, a good design IMO as C64 power supply is barely enough for C64 with a couple small accessories like joysticks and cart), SD card slot, and LCD.
I've removed the LCD and tested it on a project (gotta love standard HD44780 displays) and it works fine. I reseated the 1284p, it is still cranky. There is no other sign of issues, the O-scope shows normal signal on data and reset line of the C64's serial port with the 1564 SDrive on. I even tried a different serial cable.
I suspected the chip may be going bad so I got a new 1284p on order and I found the firmware that I could use to flash the new chip. However the firmware file I found contains a bunch of files ending in .c and .h extension so I have no idea how to use those. I don't think the creator used Arduino for the coding or uploading code.
Any idea how do I compile and upload them to the 1284p? Another issue is I only have Uno board with socket, all other Arduino has soldered on chip (nano, mega256, etc) so straight chip swap is out. I could run jumper wires from unsocketed Uno board to a breadboard but I can't find any wiring diagram for programming 1284p
Programming via Arduino ISP is the same for 1284P. You have to connect ISP wires to appropriate pins which are on different positions as 328P has.
You have to provide more info about the firmware. It couldn't be a problem to compile if it is complete. Is there any
.HEX file?
There is no hex file in the firmware download. 
So you have to built it from source. What 's about the link to firmware? Is this one?
http://www.c64sdcard.hu/en/files/src.zip
It looks good. It sholdn't be a problem to built it.
Yes it is that zip file but I have no idea how to upload the file. Arduino IDE does not handle a zip file containing a bunch of c and h files (unless I used the wrong menu?), there is no hex file and I don't know what the creator used to compile with.
Did reply #1 not meet your needs? You don't need any extra files. You just need to hook up some jumper cables as shown.
@Nick, it is a software for the MCU without the bootloader (just after brief look). It is not exactly Arduino but you tutorial for SW loading should work.
@wilykat
You've provided poor information about your devices and setup. It is not easy to help you if we have to investigate first.
Anyway, the zip contains source code files not the software to be able uploaded directly to MCU. You have built an executable image first and then to load it to the ATmega. You can use Arduino SW for compiling. Unpack the zip to the folder. AVR tools must be reachable from this folder, set the path if not. Use 'make' command to build HEX. Then connect everything as Arduino ISP setup with your UNO and upload it via 'avrdude' command directly or via bootloader (the question is if there will be a room for both, but probably yes).
Here is a picture with wiring setup example for upload.
